6.5
Research: Automatic Takeoff and Landing
Joseph
Younts
Embry
Riddle Aeronautical University Worldwide
ASCI
638: Shawn Wynn
April
2017
Automatic Takeoff and Landing
The
Boeing 737 is a manned aircraft that is capable of automatic landings at
airports that are equipped for specific categories of instrument landing system
(ILS) approaches. The various categories of ILS approaches have different
visibility minimums, and depending of the requirements and certification of the
aircraft, automatic landings are an option available to the pilots. General
Atomics Aeronautical Systems, Inc., a manufacturer of unmanned aerial vehicles
(UAVs) announced in 2012 that the MQ-9 Reaper had successfully completed 106
full stop automatic takeoff and landing capability (ATLC) landings. For manned
aircraft, particularly for commercial airliners, automatic landings have proven
to be useful in stressful situations, but the system allows the pilot to simply
switch the autopilot off if the pilot wants to hand fly the aircraft to
landing.
The
Boeing 737 autolanding features are normally completed during low visibility
weather conditions. Autolanding was designed as a safety feature to allow an aircraft
to be landed under poor weather conditions in which a conventional approach
would be hazardous and insufficient (Autoland, 2015). The autopilot system on
the 737 does have a feature that allows the pilot to disengage the autolanding
feature in order to hand fly the aircraft in the event that the autolanding
feature malfunctions. This procedure ensures that the pilot can be the final
authority of the aircraft instead of relying on the aircraft computers to do
all the work and function correctly 100% of the time. After an autolanding is
completed, the pilot will take over the aircraft in order to taxi the aircraft
off the runway and park the aircraft. “Some autoland systems require the pilot
to steer the aircraft during the rollout phase on the runway after landing,
among them Boeing´s fail passive system on the BOEING 737-700 NG, as the
autopilot is not connected to the rudder” (Autoland, n.d., para. 2). The
operations for autopilot for the 737 will be covered during training. The 737NG
has several failsafe systems in the event that the autoland function fails. If
the 2 backup systems fail, the system will recognize the issue and will about
the autoland function (Autoland, 2015). This is not so much a limitation as
much as it is an excellent design to prevent the aircraft from continuing an
approach that the system cannot achieve. The pilot can take the aircraft and
hand fly the approach, safely landing the aircraft. This author believes future
variants of any Boeing aircraft should have the autoland system that is on the
737NG. The failsafe features on the 737 NG can prevent the approach from being
continued while the pilot is alerted.
The
General Atomics MQ-9 Reaper is a UAV that was tested for automatic takeoff and
landing capabilities in 2012. In 2012, General Atomics announced that the MQ-9
Reaper successfully completed 106 full-stop automatic takeoff and landings. These
automatic takeoff and landings were the first for a multi mission aircraft
(Predator B Demonstrates Automatic, 2012). General Atomics has stated that the
aircraft was able to track the centerline, decelerate smoothly, and apply
reverse thrusters and full brakes at the necessary speeds to slow the aircraft
without damaging any systems on the aircraft (Predator B Demonstrates Automatic,
2012). After the 106 takeoff and landings, General Atomics began working to
expand the abilities of the MQ-9 Reaper. For more effective takeoffs and
landings, the Reaper is being designed to operate in higher winds, carry
increased payloads, new GPS enhancements, and terrain avoidance systems with
adjustable glideslope abilities (Predator B Demonstrates Automatic, 2012). The
system being used on the Reaper has been developed from the Gray Eagle UAS
which has over 10,000 automatic takeoff and landings.
The
ability to take off and land automatically would allow Reaper operators to use
more runways while taking the control link off the frequency band (Drew, 2016).
The senior director of strategic development, Chris Pehrson stated that MQ-9
Reapers have the ability to land on 3,000 foot runways. However, due to the UAV
being operated manually from a control station, the Air Force requires an extra
1,000 feet of runway on each end of the runway to increase the safety margins
during landings (Drew, 2016). This means the Reaper requires at least 5,000
feet of runway to land during manual operations. However, with the ability to
take off and land automatically, the Reaper can land in the same position on
the runway consistently, reducing the require amount of runway needed to land.
This allows the Reaper to land at more airports around the world if the runway
has at least 3,000 feet available for landings (Drew, 2016).
The
information regarding automatic takeoff and landings for the Reaper is scarce,
but the design for the system would increase safety if the operator could take
over the UAV in the event of a system failure during automatic takeoff and
landings. However, the issue that arises with this lies with the length of the
runway. If the required amount of runway for manual landings is 5,000 feet, an
operator may be put into the position of having to fly to another airport which
could be many miles away. Similarly to manned aircraft autopilot systems, the
operator should be alerted in the event of a malfunction. This would increase
safety and ensure that the aircraft does not crash by itself. In addition to
standard training procedures, new and current operators will be required to
learn the ins and outs of the abilities of the MQ-9 Reaper when it comes to automatic
takeoffs and landings.
Overall,
for both manned and unmanned aircraft, the pilot or operator must understand
the abilities of the aircraft in regards to takeoffs and landings. As
technology changes, manned aircraft will become capable of automatic takeoffs.
This will require aircraft manufacturers to create new fail-safe systems to
prevent the aircraft from continuing an approach if there is a malfunction. The
pilot or operator should be alerted and allowed to hand fly the approach to
ensure a safe landing.
References
Autoland. (2015, July 11).
Retrieved from http://www.boeing737pilot.net/autoland/
Autoland. (n.d.). Retrieved from http://www.skybrary.aero/index.php/Autoland
Drew, J. (2016, May 04). USAF to
automate MQ-9 takeoffs and landings. Retrieved from https://www.flightglobal.com/news/articles/usaf-to-automate-mq-9-takeoffs-and- landings- 424975/
Predator B Demonstrates Automatic
Takeoff and Landing Capability. (2012, September 17). Retrieved from http://www.ga.com/predator-b-demonstrates-automatic-takeoff-and-landing-capability
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